The search for oil and gas offshore has moved drilling and production activity further and further out to sea into deeper waters. Part of any such oil and gas well production activity is the need for underwater flowline connections for connecting together or repairing flowlines located subsea. Such subsea flowline connectors can be installed utilizing divers or Remote Operated Vehicles (ROV), which have become more and more common due to the necessity of working at increasing water depths. Further, the need to make necessary repairs to existing subsea pipelines continues the challenge of making underwater repair connections that can be efficiently implemented by divers. The utilization of Remote Operated Vehicles as well as other hydraulically actuated equipment allows such underwater pipeline connections to be made utilizing at least in part hydraulic fluid under pressure. However, the utilization of hydraulic fluid under pressure to make such flowline connections requires such flowline connectors to have highly efficient gripping and sealing mechanisms. Another problem with such hydraulically actuated flowline connectors is the operability and reliability of mechanisms for locking the gripping and sealing members in actuated positions. These problems must be solved utilizing structural elements in efficient structural relationships to allow for efficient hydraulic actuation and highly reliable locking mechanisms to hold the various elements of the flowline connector in locked position.
There are a number of patents directed to various types of flowline connectors. For example, U.S. Pat. No. 4,180,285 of Reneau discloses a ball-type connector wherein the female housing includes a cup-shaped receptacle for receiving the curved surface of the male or ball member. The ball is pivotal relative to the cup-shaped receptacle and a collar is mounted about the ball and is moved to various positions through a series of hydraulic piston assemblies. The collar and the cup-shaped receptacle are joined together utilizing a ring which is moveable radially inwardly by means of a hydraulically actuated tapered wedge. In this type of ball-type connector, there is no utilization of separate gripping and sealing elements which are hydraulically actuatable. There are many other hydraulically-actuatable underwater connectors including, for example, U.S. Pat. Nos. 3,874,706; 3,944,263; and others cited in U.S. Pat. No. 4,180,285. Examples of mechanically actuatable flowline connectors include U.S. Pat. Nos. 4,109,945; 4,290,632 and 4,330,143. U.S. Pat. No. 4,109,945 dicloses an apparatus for connecting together flowline end portions which include a generally cylindrical housing having separated sealing and gripping mechanisms. The gripping mechanism includes opposing camming areas for moving collet portions radially inwardly into engagement with a flowline. The collet member as well as the sealing elements are mechanioally actuated utilizing bolt-actuated flange structures. U.S. Pat. No. 4,290,632 discloses a mechanically actuatable apparatus for connecting together flowline portions which include separate sealing and gripping sections for engaging a flowline member. The sealing and gripping sections are both actuated by bolt members which serve to axially move an internal, flanged member. U.S. Pat. No. 4,330,143 discloses another version of such mechanically actuated flowline connectors which includes a single collet member which is actuated by a bolt-type actuating mechanism.